Activating high-speed train configurations in wireless communications

Abstract

Aspects of the present disclosure describe activating a high speed train (HST) configuration for communicating with a cell in a HST based communications environment. A first signal including an HST activate indication to activate a HST configuration can be received from a cell. The HST configuration can be activated based at least in part on the HST activate indication. One or more subsequent signals can be communicated with the cell using the HST configuration based at least in part on the HST activate indication.

What is claimed is: 
     
       1. A method for activating a high speed train (HST) configuration for communicating with a cell in a HST based communications environment, comprising:
 receiving, by a user equipment (UE) from the cell, a physical broadcast channel signal with a master information block (MIB) including an HST activate indication to activate a HST configuration; 
 activating, by the UE based at least in part on the HST activate indication, the HST configuration; and 
 communicating, by the UE based at least in part on the HST activate indication, one or more subsequent signals with the cell using the HST configuration. 
 
     
     
       2. The method of  claim 1 , wherein the HST configuration indicates a demodulation reference signal (DM-RS) pattern, wherein communicating the one or more subsequent signals includes receiving, from the cell, one or more subsequent signals with one or more system information blocks (SIBs), and further comprising processing the one or more subsequent signals based on a DM-RS received according to the DM-RS pattern. 
     
     
       3. The method of  claim 1 , further comprising receiving a SIB which includes a second HST activate indication, and further comprising communicating one or more subsequent downlink control channel or downlink shared data channel signals transmitted by the cell based on the second HST activate indication. 
     
     
       4. The method of  claim 1 , further comprising receiving a downlink control information (DCI) message in a downlink control channel which includes a second HST activate indication, and further comprising communicating one or more subsequent downlink shared data channel signals transmitted by the cell based on the second HST activate indication. 
     
     
       5. The method of  claim 4 , wherein the second HST activation indication corresponds to a limited time period for which a second HST configuration is activated, after which the second HST configuration is deactivated for communicating, by the UE, with the cell or one or more other cells. 
     
     
       6. The method of  claim 5 , wherein the limited time period is one or more subframes, one or more slots, or one or more symbols. 
     
     
       7. The method of  claim 5 , further comprising reporting a UE condition to the cell, wherein the limited time period is determined based at least in part on the UE condition. 
     
     
       8. The method of  claim 1 , wherein the HST configuration indicates a demodulation reference signal (DM-RS) pattern that includes more frequency resources per period of time than a non-HST DM-RS pattern, and further comprising processing the one or more subsequent signals based on the DM-RS pattern indicated in the HST configuration. 
     
     
       9. The method of  claim 8 , further comprising receiving the one or more subsequent signals as single frequency network signals from a plurality of remote radio heads (RRHs). 
     
     
       10. The method of  claim 9 , further comprising receiving independent tracking reference signals from the plurality of RRHs for determining Doppler tracking for each of the plurality of RRHs. 
     
     
       11. A method for activating a high speed train (HST) configuration for communicating with a cell on a HST, comprising:
 transmitting, from a cell to a user equipment (UE), a physical broadcast channel signal with a master information block (MIB) including an HST activate indication to activate a HST configuration; and 
 communicating, by the cell with the UE, one or more subsequent signals based on the HST configuration. 
 
     
     
       12. The method of  claim 11 , wherein the HST configuration indicates a demodulation reference signal (DM-RS) pattern, wherein communicating the one or more subsequent signals includes transmitting, to the UE, the one or more subsequent signals with one or more system information blocks (SIBs), and further comprising transmitting, to the UE and based on the DM-RS pattern, one or more DM-RSs for processing the one or more subsequent signals. 
     
     
       13. The method of  claim 11 , further comprising transmitting a system information block (SIB) which includes a second HST activate indication, and further comprising communicating one or more subsequent downlink control channel or downlink shared data channel signals based on the second HST activate indication. 
     
     
       14. The method of  claim 11 , further comprising transmitting a downlink control information (DCI) message indicated in a downlink control channel which includes a second HST activate indication, and further comprising communicating one or more subsequent downlink shared data channel signals based on the second DST activate indication. 
     
     
       15. The method of  claim 14 , wherein the second HST activate indication corresponds to a limited time period for which a second HST configuration is activated. 
     
     
       16. The method of  claim 15 , wherein the limited time period is one or more of one or more subframes, one or more slots, or one or more symbols. 
     
     
       17. The method of  claim 15 , further comprising:
 receiving a condition from the UE; and 
 determining the limited time period based at least in part on the condition. 
 
     
     
       18. The method of  claim 11 , wherein the HST configuration indicates a demodulation reference signal (DM-RS) pattern that includes more frequency resources per period of time than a non-HST DM-RS pattern used in transmitting non-HST signals. 
     
     
       19. The method of  claim 18 , wherein transmitting the one or more subsequent signals comprises transmitting the one or more subsequent signals as single frequency network signals from a plurality of remote radio heads (RRHs). 
     
     
       20. An apparatus for activating a high speed train (HST) configuration for communicating with a cell in a HST based communications environment, comprising:
 a transceiver for communicating one or more wireless signals via one or more antennas; 
 a memory configured to store instructions; and 
 one or more processors communicatively coupled with the transceiver and the memory, wherein the one or more processors are configured to:
 receive, from the cell, a physical broadcast channel signal with a master information block (MIB) including an HST activate indication to activate a HST configuration; 
 activate, based at least in part on the HST activate indication, the HST configuration; and 
 communicate, based at least in part on the HST activate indication, one or more subsequent signals with the cell using the HST configuration. 
 
 
     
     
       21. The apparatus of  claim 20 , wherein the HST configuration indicates a demodulation reference signal (DM-RS) pattern, wherein the one or more processors communicate one or more subsequent signals at least in part by receiving, from the cell, one or more subsequent physical broadcast channel signals with one or more system information blocks (SIBS), and wherein the one or more processors are further configured to process the one or more subsequent signals based on a DM-RS received according to the DM-RS pattern. 
     
     
       22. The apparatus of  claim 20 , wherein the one or more processors are further configured to receive a SIB which includes a second HST activate indication, and wherein the one or more processors are further configured to communicate one or more subsequent downlink control channel or downlink shared data channel signals transmitted by the cell based on the second HST activate indication. 
     
     
       23. The apparatus of  claim 20 , wherein the one or more processors are further configured to receive a downlink control information (DCI) message in a downlink control channel which includes a second HST activate indication, and wherein the one or more processors are further configured to communicate one or more subsequent downlink shared data channel signals transmitted by the cell based on the second HST activate indication. 
     
     
       24. The apparatus of  claim 23 , wherein the second HST activate indication corresponds to a limited time period for which a second HST configuration is activated, after which the second HST configuration is deactivated for communicating, by the UE, with the cell or one or more other cells. 
     
     
       25. The apparatus of  claim 20 , wherein the HST configuration indicates a demodulation reference signal (DM-RS) pattern that includes more frequency resources per period of time than a non-HST DM-RS pattern, and further comprising processing the one or more subsequent signals based on the DM-RS pattern indicated in the HST configuration. 
     
     
       26. An apparatus for activating a high speed train (HST) configuration for communicating with a cell on a HST, comprising:
 a transceiver for communicating one or more wireless signals via one or more antennas; 
 a memory configured to store instructions; and 
 one or more processors communicatively coupled with the transceiver and the memory, wherein the one or more processors are configured to [cause the apparatus to]:
 transmit, to a user equipment (UE), a physical broadcast channel signal with a master information block (MIB) including an HST activate indication to activate a HST configuration; and 
 communicate, with the UE, one or more subsequent signals based on the HST configuration. 
 
 
     
     
       27. The apparatus of  claim 26 , wherein the HST configuration indicates a demodulation reference signal (DM-RS) pattern, wherein the one or more processors are configured to communicate the one or more subsequent signals at least in part by transmitting, to the UE the one or more subsequent signals with one or more system information blocks (SIBs), and wherein the one or more processors are further configured to transmit, to the UE and based on the DM-RS pattern, one or more DM-RSs for processing the one or more subsequent signals. 
     
     
       28. The apparatus of  claim 26 , wherein the one or more processors are further configured to transmit a system information block (SIB) which includes a second HST activate indication, and wherein the one or more processors are further configured to communicate one or more subsequent downlink control channel or downlink shared data channel signals based on the second HST activate indication. 
     
     
       29. The apparatus of  claim 26 , wherein the one or more processors are further configured to transmit a downlink control information (DCI) message indicated in a downlink control channel which includes a second HST activate indication, and wherein the one or more processors are further configured to communicate one or more subsequent downlink shared data channel signals based on the second HST activate indication. 
     
     
       30. The apparatus of  claim 26 , wherein the HST configuration indicates a demodulation reference signal (DM-RS) pattern that includes more frequency resources per period of time than a non-HST DM-RS pattern used in transmitting non-HST signals.